A planar inverted-F antenna (PIFA) type is mainly used in a multi-band built-in antenna which supports communication in a plurality of frequency bands using a single wireless communication terminal (see Japanese Unexamined Utility Model Registration Application Publication No. 7-14714 and Japanese Unexamined Patent Application Publication No. 2002-344233).
Furthermore, to achieve a wider bandwidth, antennas including a parasitic element connected to a ground (GND) plate have been dominant (see Japanese Unexamined Utility Model Registration Application Publication No. 62-161410).